Cost-effective and scalable rectifier design for multiple piezoelectric power sources with improved performance

Multiple piezoelectric power sources are used for extending the bandwidth or the multi-direction operation capability of the vibration harvesters. Typical rectifier configurations including parallel or series connection before a shared rectifier or one rectifier per source are usually used for regulating the multiple sources. The problem of charge cancelation arises for the shared rectifier configuration while diodes are too many for the configuration of one rectifier per source. In this article, improved rectifier design is proposed for multiple sources by introducing a common ground branch. The improved scalable rectifier design is capable of unifying more than one sources of different voltage polarity to power the load without charge cancelation, thus promising better performance than the aforementioned configurations. The power enhancement is verified through simulations and experiments with a maximum boost of 91.9% and the effective bandwidth is increased by 23.3% at least. In particular, the design has the advantage of cost saving by reducing the diodes to almost the half in comparison with the configuration of one rectifier per source.